Description

After the Canterbury earthquakes, regulations governing foundations changed. Initially only for the Canterbury region, they were later rolled out around New Zealand. What are the changes and what do they mean?

Many designers and builders know that, starting 29 November 2021, new rules for liquefaction kicked in. The official wording is longer and more formal, of course, but to sum it up in a nutshell – if you want to build a home on land that is prone to liquefaction, you need an engineered foundation.

What does engineered foundation mean? What does liquefaction-prone mean? And why did we change the rules to begin with?

Build magazine spoke to industry specialists Mike Jacka, Senior Geotechnical Engineer at Tonkin & Taylor, Tim Farrant, Engineering Manager at MBIE, and Marie-Claude Hébert, Senior Geotechnical Engineer at Christchurch City Council, to explain all this in an easy-to-understand way.

Scope

This article includes:

• Canterbury earthquakes changed everything
• Technical categories introduced in response
• Roll-out for rest of country
  • Defining liquefaction risk
  • Foundation types rolled out in 2021
• The reality today
• Key technical details